Autofocus systems rely on one or more sensors to determine correct focus. Data collected from an autofocus sensor is used to control an electromechanical system that adjusts the focus of an optical system of a camera. When an image is taken of a subject that is on the ground by the camera that is also on the ground, the subject may in focus while the background is out of focus. This is because the range from the camera and to the subject is different than the range from the camera to the background. In an air-to-ground application, ranges from an airborne camera to the ground and to people and objects on the ground are nearly the same. As such, the challenge to autofocusing images taken from the air is focusing the entire image and not just a portion. Other challenges, which are particularly prevalent to surveillance applications, include autofocusing images quickly and low light conditions.